MONTREAL – In early September when the Yankees were enmeshed in a struggle to reach the playoffs, Joe Torre kept Derek Jeter and his aching knee out of a game in Kansas City.

Now, with the Rangers engaged in a similar battle in their sport, Tom Renney may have to make a similarly tough call regarding Brendan Shanahan and his aching knee, hip, groin and hamstring, all of which have compromised No. 14’s ability to skate with authority the last month.

“Brendan and I have had a number of good discussions about where the cross-hairs of the decision line up,” said Renney, whose team carries a two-game winning streak into this afternoon’s match here against the Canadiens. “It’s up to Brendan to be honest with me about his health, and it’s up to me to be honest with him and myself about his level of performance.

“Brendan is very important in the room and on the bench. He’s a voice that helps sell what we need to sell about reminding the group about commitment to the team concept. He’s a hugely valuable guy to whom I feel very comfortable turning to in a game’s most crucial moments.”

This afternoon’s game marks the third in four days and fourth in six days for the Rangers. They’ll embark on another four-in-six beginning Tuesday. After that, the Blueshirts will have five days off. Renney and Shanahan both are targeting that stretch as the period in which the winger will be able to rest and recover from the original knee injury he sustained in Edmonton on Jan. 5.

“Everyone at this stage of the season is playing through injuries of some sort, and with the situation we’re in where every point is significant, I wouldn’t feel right about not playing,” Shanahan told The Post. “I’m not 100 percent, but I don’t feel as if the problem has gotten worse over the last two or three weeks.

“If it does get worse, though, I’m going to have to pull myself out. I’ve given my word to Tom that I’ll be honest with him about my condition. The last thing I want to do is hurt the team by playing.”

Shanahan has scored twice in the 11 games he played since suffering the injury on an open-ice collision, yet he continues to lead the team with 17 goals. Playing on a line with down-low workers Sean Avery and Brandon Dubinsky allows him to assume a third-man high sniper’s stance in the offensive and thus avoid a lot of the heavy lifting.

“I feel as if I’ve been contributing to wins, and that I’ve been one of the guys playing a role the last couple of weeks in which we’ve begun to correct a lot of the little things that had been problems,” Shanahan said. “And so I don’t want to come out.

“If I were to sit [today] or Tuesday, I don’t think that would provide much benefit. If the leg doesn’t improve at all or gets worse the next few days, then maybe coming out of the lineup next weekend right before the five-day break would be helpful, in that it would extend the rest period to seven or eight days.

“That being said, I’m from the school where you play through pain and you play through injuries. That’s the way I was taught.”